At 95 mph, most golfers should start with a Regular flex driver shaft if their tempo is smooth, and move to Stiff if their transition is quick or their speed is closer to 100. On the Steadfast Jupiter One, Regular covers 90–99 mph (241 CPM, 55 grams) and Stiff covers 100–109 mph (258 CPM, 58 grams), so the choice at 95–105 usually comes down to where you sit in that range and how you swing.
That's the quick answer. The rest of this guide covers why this range is so easy to get wrong, what to look at besides flex, and how to check you've picked the right one before you spend anything.
Where do you land? A quick check
Before the details, answer these honestly:
- Do you know your driver swing speed, or are you guessing from your distance?
- Is your swing smooth and rhythmic, or quick off the top?
- When you miss, does the ball start left and leak right, or balloon with too much spin?
If you don't know your number, a launch monitor session at a range or fitting studio will tell you in minutes. If you're not sure about your tempo, ask a playing partner. They usually know.
Why 95–105 mph is a tricky range
This range covers a lot of golfers, from strong mid-handicappers to low single-digit players. It sits right on the line between Regular and Stiff on most flex charts, and that's where "one size fits most" shafts stop fitting.
A shaft that's too soft for you can feel whippy, add spin, and let the face lag or twist. A shaft that's too stiff won't load properly, and that tends to show up as thin contact, a weak low fade, and less distance. Our guide on what happens when a golf shaft is too flexible covers the first problem in more detail, and the Driver Shaft Flex Chart covers the full range of speeds.
One thing worth saying plainly: 105 mph is a strong swing, but it isn't tour speed. Tour averages are well above it, so don't pick a shaft as if you swing like a pro. That's one of the most common mistakes at this speed.
Regular or Stiff? Tempo breaks the tie
Swing speed gives you a starting point, and tempo decides the close calls. Two golfers at 97 mph can need different shafts if one swings smoothly and the other attacks the ball from the top.
| Your swing | Start with |
|---|---|
| 90–96 mph, smooth tempo | Regular |
| 97–99 mph, smooth tempo | Regular |
| 97–99 mph, quick transition | Try both. This is the true gray zone |
| 100–105 mph, smooth tempo | Stiff |
| 100–105 mph, quick transition | Stiff |
If your number falls within 3 or 4 mph of a boundary, the way you swing matters as much as the number.
What else matters besides flex
Flex gets all the attention, but three other things decide how a shaft plays for you.
Weight. Shaft weight affects tempo and control. A common starting range for this swing speed is roughly 55 to 65 grams. Too heavy and you can lose clubhead speed. Too light and your timing can become inconsistent. The Jupiter One is 55 grams in Regular and 58 grams in Stiff, so both sit at the lighter end of that range.
Torque. Torque is how much a shaft twists during the swing. Lower torque means the clubface stays squarer through impact, so off-center hits stay closer to your target line. It matters more as speed goes up, because a faster swing puts more twisting force on the shaft.
Balance. The weight balance between the head and the shaft affects how smoothly the club moves through impact. A well-balanced setup lets the head lead naturally, which helps you deliver the face squarely. Steadfast built the Jupiter One with torque and balance as its first priorities for this reason.
What should your launch and spin look like?
Most golfers at this speed fall into one of two camps:
- Distance first. A slightly lighter shaft and a mid-to-high launch with a bit more spin helps you carry the ball farther.
- Control first. A firmer shaft with lower torque gives up a little peak distance in exchange for tighter dispersion.
Neither is wrong. What matters is knowing which camp you're in, and your typical miss tells you. A low fade points toward control. A high, ballooning ball points toward spin you need to bring down.
Where the Jupiter One fits
Here are the Jupiter One specs from the product page, including the two flexes on either side of your range:
| Flex | Swing speed | Weight | CPM | Length |
|---|---|---|---|---|
| Senior | 70–89 mph | 50 g | 227 | 45.5 in |
| Regular | 90–99 mph | 55 g | 241 | 45.5 in |
| Stiff | 100–109 mph | 58 g | 258 | 45.5 in |
| X-Stiff | 110–129 mph | 61 g | 273 | 45.5 in |
CPM is a measure of stiffness, so a higher number means a stiffer shaft. Notice the shaft gets heavier as the flex gets stiffer.
Flex isn't standardized across brands, so a "Stiff" from another maker may play firmer or softer than ours. If you're comparing brands, compare weight and CPM, not just the letter.
Steadfast ran its own head-to-head test on a single driver head against two unnamed aftermarket shafts. In that test, the Jupiter One produced higher ball speed, lower spin, and about 10 to 12 more yards of carry. That's a data point from the company that makes the shaft, on one head, so treat it as a reason to test it yourself, not as proof it will do the same for your swing. The product page also covers a 60-day Shaft Flex Satisfaction Guarantee if the flex isn't right.
For smoother swingers who want a lighter option, there's also the Jupiter Lite Driver Shaft.
Five things to check before you buy
- Write down your current shaft. Note the model, flex, and weight. It's the baseline you're trying to beat.
- Use real numbers. Launch angle and spin from a launch monitor beat guessing every time.
- Look at your usual miss. A consistent miss is useful information. An inconsistent one often points to a flex or weight mismatch.
- Don't assume stiffer is better. Plenty of golfers around 95 mph play best in a shaft that loads a little more. We covered why in Do Pros' Shaft Choices Actually Matter for Your Game?
- Check it fits your driver. The Jupiter One comes with the adapter and grip already installed, for a long list of major brands, in right- or left-hand. If you're not sure about your head, our compatibility guide walks through it.
Not sure where you land? The Shaft Selector Quiz asks a few quick questions about your swing and points you to a flex.
Questions, answered
What flex shaft should I use with a 95 mph swing speed? Most golfers start with Regular, especially with a smooth tempo. If you have a quick transition or you're closer to 100 mph, try Stiff.
What driver shaft weight is best for 95 mph? A common starting range is roughly 55 to 65 grams. The Jupiter One is 55 grams in Regular and 58 grams in Stiff.
Is 100 mph a Regular or Stiff swing speed? On the Jupiter One, 100 mph is where Stiff starts. Regular covers 90–99 mph.
Does shaft flex really matter at 95 mph? Yes. At this speed you're right on the Regular and Stiff border, so a mismatch is easy to make and shows up as inconsistent contact and dispersion.
What if I swing faster than 105 mph? Then you're moving toward Stiff and X-Stiff territory, with different weight and stability needs. See our guide to the best driver shaft for high swing speed players.
What if I swing slower than 90 mph? Read our guide to the best driver shaft for slow swing speed.
Keep building your setup
- Take the Shaft Selector Quiz to get a starting flex recommendation in about a minute.
- Check the Driver Shaft Flex Chart to compare your swing speed against every flex.
- Learn about our carbon fiber shafts to see how low-torque construction works.
- Read How Often Should You Actually Get Refit? if it's been a while since you checked your setup.
- Shop the Jupiter One Driver Shaft in Regular or Stiff once you know your number.
The bottom line
At 95–105 mph you're on the Regular and Stiff border, so your tempo matters as much as your number. Start with Regular if you're smooth or under 100, Stiff if you're quick or over it, and compare weight and CPM rather than the flex letter when you shop across brands. Check your number and your miss first, then choose the shaft.